1. Field of the Invention
The invention relates to a device for feeding fluid, in particular cooling water for the spraying of picks, into the inside of a shearing drum, the rotary drive of which has at least one gear reduction stage inside the hollow shearing drum.
2. Description of the Related Art
For the so-called internal spraying of picks, it has already been disclosed in conjunction with rotatingly mounted shearing heads, which differ from shearing drums in that they are much shorter in the axial direction and, unlike shearing drums, can be mounted close to their axis of rotation, to carry out water feeding via axial channels in cases in which reduction gear mechanisms or stages of such a reduction gear mechanism are arranged in the hollow shearing head itself. In the case of shearing drums, a mounting takes place over the axial length of the drum, usually at several points, the mounting usually taking place at quite a large diameter and close to the outer surface of the drum. It is known to make such shearing drums hollow and it is also known to arrange stages of a reduction gear mechanism inside such shearing drums in order to be able to keep the diameter of the drive shafts smaller. However, with most designs of drive there is no possibility for axial feeding of fluid and therefore, for shearing drums, a spraying of the picks themselves via feed lines arranged inside the shearing drum is not readily possible.
It is also known in the case of shearing drums to extend lateral regions of the shearing drums in the axial direction by hydraulically driven, extendable components, with the result that a widening of the drum is obtained. Fluid medium must likewise be fed for the hydraulic drive of such shearing drum widenings and, since the drives of such drum widenings are set in rotation with the shearing drum, rotating lead-throughs are required for the feeding of fluid. If, as is usual in the case of known drive apparatuses, a continuous shaft is used as gear output shaft, the rotating lead-through can only ever be provided outside the axial area and consequently at quite a large radius, as a result of which sealing problems arise.